B83

The B83 is an unguided variable-yield thermonuclear weapon developed by the United States during the late 1970s. The weapon entered service in 1983, replacing several earlier systems including the B28, B43, and B53. Its development was based partly on the terminated B77 program, which was canceled due to cost overruns. Nuclear component test firings associated with the design were conducted during the Operation Anvil underground nuclear test series between 1975 and 1976. The B83 was the first United States nuclear weapon designed from its inception to utilize insensitive explosives in the trigger lens system to prevent accidental detonation. In 2022, the United States government announced plans to retire the weapon, with the B61-13 planned as its replacement.

The weapon features a nose-heavy layout with the warhead mounted in the forward section. It is designed for high-speed carriage and delivery at both high and low altitudes. For low-altitude delivery, the bomb utilizes a Kevlar ribbon parachute retardation system for deceleration. Delivery modes include free-fall, retarded, contact, and laydown, allowing for either air-burst or ground-burst detonation. Security and authorization control are provided by a Category "D" Permissive Action Link and a command disablement system to prevent unauthorized activation. The weapon has a variable yield, adjustable from the low kiloton range up to a maximum of 1.2 megatons. The physics package of the weapon has also been studied for potential use in asteroid impact avoidance strategies and was evaluated for the Robust Nuclear Earth Penetrator program.

The B83 is operated exclusively by the United States. It is currently certified for carriage on the B-2 Spirit bomber and is planned for integration onto the future B-21 Raider. The weapon was previously carried by the B-52 Stratofortress and B-1B Lancer; however, nuclear capability has been removed from the B-1B, and the B-52 no longer operates gravity nuclear weapons.